On paper, the giants of American insurance look unassailable. UnitedHealth Group, Elevance Health and Cigna each generate hundreds of billions of dollars in annual revenue and cover tens of millions of people. To many investors, that scale suggests power — and, by extension, profit.
But a closer look at how efficiently those companies turn revenue into earnings tells a different story.
An analysis of 20 major US insurance businesses, based on 2025 financial results, finds that the industry’s true profit leaders are not necessarily its biggest names. A mix of mid‑size carriers and specialist firms — Allstate, Cincinnati Financial, Markel Group and Marsh & McLennan among them — top a ranking that blends operating margin, net margin and earnings per share. The giants still earn more dollars overall. They simply keep less of each dollar they collect.
Allstate, better known to many Americans for its television commercials than for balance‑sheet prowess, comes out No. 1. In 2025 the company generated an operating margin of about 20.2 percent and a net margin of 15.2 percent, while producing diluted earnings per share of $38.06. That mix of rich margins and high profit per share puts it ahead of Cincinnati Financial and Markel, which also deliver double‑digit margins and strong earnings per share.
The ranking offers a different answer to a simple question: Who is really the most profitable insurance business in America?
The exercise starts from a basic problem in judging insurance companies. The industry’s biggest players — especially in health care — operate on relatively thin margins but enormous revenue bases. That makes it easy to confuse size with profitability.
To look past scale, the analysis relies on three measures from 2025:
Each company is ranked on those three metrics. The average of those ranks creates a “profitability score”. The resulting league table is less a list of who writes the most premium and more a map of who squeezes the most out of every dollar that comes in.
On that measure, UnitedHealth looks less dominant. It produced almost $18.7 billion in operating profit on $447.6 billion in revenue in 2025, but its operating margin was only about 4.2 percent and its net margin 2.7 percent. Elevance Health reported similar figures, with operating margin just above 4 percent and net margin under 3 percent.
Brown & Brown, a Florida‑based insurance broker that handles policies for others rather than bearing the risk itself, sits at the opposite end of the spectrum. In 2025 it earned nearly 29.1 percent on each dollar of revenue at the operating level and about 17.2 percent at the net line — the fattest margins in the group. Its earnings per share, $3.16, are small in absolute terms, but on a percentage basis it extracts far more profit from each premium dollar than the health‑care behemoths.
Cincinnati Financial converted roughly 24 percent of its 2025 revenue into operating profit and 18.9 percent into net income, while earning $15.17 per share. Marsh & McLennan, the global broker and consulting giant, posted an operating margin of about 24.1 percent and a net margin of 15.4 percent, with earnings per share of $8.43. Travelers, the familiar red‑umbrella brand, turned in operating and net margins of roughly 16.8 and 12.8 percent and earnings per share of $27.43.
None of these companies tops the industry in premiums written. All of them sit near the top of the profitability ranking.
If the ranking were based solely on earnings per share, Markel Group would win in a landslide. The Richmond, Va., specialty insurance business reported diluted earnings per share of $169.22 in 2025 — roughly four times Allstate’s level and more than seven times Cincinnati Financial’s. Its operating margin, at about 18 percent, and net margin, at 13.1 percent, also place it firmly in the profitability elite.
But Markel illustrates a hazard in focusing only on per‑share earnings. Over the 2021 to 2025 period, its earnings per share swung from a triple‑digit profit to a deep loss and back again before settling near $170. Its average operating margin over those five years, close to 17 percent, was robust. Yet its long‑run earnings‑per‑share growth rate works out to roughly minus 1 percent a year, a reminder that the path to those profits has been bumpy.
Other companies show a steadier pattern of compounding.
Travelers increased its earnings per share at roughly 17 percent a year from 2021 through 2025, helped by consistent underwriting results and disciplined capital management. Progressive, which built its brand on aggressive pricing in auto insurance, lifted its earnings per share about 36 percent annually over the period, as its operating margin climbed into the mid‑teens and averaged roughly 10 percent over five years.
The Hartford’s numbers are more dramatic still. In 2021 it earned $1.47 a share. By 2025, that figure had climbed to $13.32 — growth of roughly 73 percent a year — while its operating margin rose to about 17.7 percent from low single digits early in the decade. Its average operating margin over the five‑year span, around 14.5 percent, suggests a business that has been fundamentally reshaped rather than lucky in a single year.
Taken together, these names form an E.P.S. aristocracy: not necessarily the largest insurance businesses, but those that consistently turn a sizable share of their revenue into earnings for each shareholder.
The diversified health insurance businesses tell a more complicated story. Their sheer scale gives them enormous absolute earnings power, but regulatory caps on margins in core lines and high medical and administrative costs keep those margins relatively slim.
UnitedHealth’s 2025 operating margin of 4.2 percent and net margin of 2.7 percent are typical of the group. Over the 2021–25 period, its average operating margin was a bit above 7 percent, and its earnings per share actually shrank at about 7 percent a year as results normalized from the unusual conditions of the pandemic years.
Elevance Health posted a 2025 operating margin just over 4 percent and a net margin of 2.8 percent, with earnings per share of $25.21. Over five years, its earnings per share grew at only about half a percent annually, even as revenue rose, and its average operating margin remained in the low single digits.
Cigna’s 2025 operating and net margins, around 3.3 and 2.2 percent, respectively, and earnings per share of $22.18 tell a similar story: solid but not spectacular profitability, supported by vast scale and relatively modest per‑share growth — roughly 9 percent a year over the period.
Centene, which focuses heavily on Medicaid and Affordable Care Act plans, struggled most visibly. In 2025 it reported an operating margin of minus 3.1 percent, a net margin of minus 3.4 percent and a diluted loss per share of $13.53. Its average operating margin over 2021–25 was barely positive.
On the profitability ranking, these economics place the health‑care giants in the middle of the pack. UnitedHealth, Elevance and Cigna cluster around companies like American International Group and W.R. Berkley. Centene sits near the bottom.
For shareholders, the contrast is straightforward. A company that earns $2 billion on $10 billion in revenue, with modest capital needs, can produce better earnings per share — and often better returns over time — than a company that earns $20 billion on $400 billion in revenue but must support a huge balance sheet and sprawling administrative structure.
Several forces help explain why mid‑size and specialist insurance businesses often outshine the giants on margins and per‑share earnings.
One is business mix. Brokers such as Marsh & McLennan and Brown & Brown are capital‑light. They arrange coverage and earn fees and commissions, but they do not carry the same reserves as traditional insurance businesses. That allows them to turn a much larger share of each dollar into profit. Brown & Brown’s average operating margin between 2021 and 2025 was just under 30 percent, the highest in the group.
Specialty carriers and reinsurers — including Markel, Cincinnati Financial, W.R. Berkley and Reinsurance Group of America — focus on narrower, often more complex lines. Expertise and pricing power in those niches can support richer margins, even if the total pool of premiums is smaller. Reinsurance Group of America, for example, posted a 2025 operating margin of about 8 percent and earnings per share of $17.69, with per‑share earnings rising about 18 percent a year over the five‑year period.
Another factor is capital intensity. Large health insurance businesses and multiline giants must hold significant capital against their liabilities and maintain extensive infrastructure to serve tens of millions of members. Even when those businesses earn healthy dollar profits, that capital base dilutes profitability on a per‑share basis.
A third is cycle timing and volatility. Property‑casualty writers such as Allstate and Progressive were hit hard in 2022 and 2023 as inflation drove up repair and replacement costs while regulators were slow to approve rate increases. Their 2025 margins look strong partly because they pushed through steep price rises and tightened underwriting later in the cycle. Whether those margins prove sustainable will depend on how competitive and political pressures evolve.
To test whether 2025 was a fluke, the analysis also examined earnings‑per‑share growth and average operating margins over the full 2021–25 period.
Progressive, Travelers and Cincinnati Financial stand out as relatively consistent performers. Each posted solid average operating margins — roughly 10 percent, 13 percent and 20 percent, respectively — and increased earnings per share at double‑digit annual rates, even after accounting for a difficult 2022.
Allstate’s numbers are more dramatic. Its earnings per share grew at roughly 66 percent a year over the period, but from a weak starting point as it recovered from earlier underwriting losses. Its average operating margin of about 8.1 percent reflects that journey from red ink back to strong profitability.
Hartford’s transformation appears more structural. With a five‑year average operating margin of about 14.5 percent and rapid, relatively steady earnings growth, it looks less like a one‑year beneficiary of pricing cycles and more like a business that has re‑engineered its economics.
At the other extreme, American International Group and Centene show the scars of restructuring and tough lines of business. A.I.G. maintained high average operating margins — close to 20 percent — but swings in its results, including a loss in 2024, left its earnings per share shrinking on balance. Centene’s 2025 loss erased much of its earlier progress.
The pattern suggests that some of the profitability leaders — Progressive, Travelers, Cincinnati Financial, Marsh & McLennan and Brown & Brown among them — are genuinely advantaged franchises, not just beneficiaries of a single good year. Others, like Allstate, appear to be riding the high point of a cycle.
For investors, the message is clear: size and brand recognition are not reliable guides to profit intensity. A portfolio built solely around the biggest health insurance businesses may capture the stability of enormous membership bases, but it will miss the high‑margin economics available in certain brokerage, specialty and reinsurance businesses.
For policyholders and regulators, the results raise a different question: who captures the economic surplus in the insurance system? High margins at brokers may reflect the value of their expertise and distribution networks, but they also add to the cost of coverage borne by individuals and businesses. Thin margins at government‑focused health plans, by contrast, reflect political decisions about how much profit is acceptable in those markets.
What is clear is that the industry’s profit engine is more complex than the towering revenue figures of its biggest players suggest. The insurance businesses that matter most to shareholders, at least on a per‑share basis, are often the ones that sit a few rows down on the league table of premium volume — quietly compounding earnings far from the top‑line spotlight.
